The works show that, using fluorescent probes, it was used to study the effect of PC-8 on changes in the dynamics of the intracellular Ca2+ content in synaptosomes of the rat brain, depending on the site of the binding of glutamate on calcium channels by a specific mediator with glutamate. To measure the amount of cytosolic Ca2+ synaptosomes, we calculated using the Grinkevich equation. It has been shown that polyphenol PC-8 binds to the glutamate-binding site of NMDA receptors, so that the conductance for Ca2+ ions is reduced through a channel blocking the effect of polyphenol PC-8 can be explained. due to its binding to the competing action of the site, the binding of glutamate to NMDA receptors.